Locking device for a picture screen



Feb. 4, 1958 E. J; PETRICK ET AL LOCKING DEVICE FOR A PICTURE SCREEN Filed Aug. 20, 1953 I United States Patent-O LOCKING DEVICE FOR A PICTURE SCREEN Edward J. Petrick and Russell E. Petrick, Park Ridge,

11]., assignors to Knox Manufacturing Company, a corporation of Illinois Application August 20, 1953, Serial No. 375,369

11 Claims. (Cl. 160-24) This invention relates to a device for locking a picture screen in taut condition when in open position.

Picture screens are commonly in loose and wrinkled condition when extended into open position from a curtain-type roller. The present invention concerns a knob for rewinding a portion of the extended screen upon the roller to apply stretching tension to the screen and a oneway lock associated with the knob to hold the screen and I the roller in their rewound position.

The primary object is to provide a device for locking an extended picture screen in taut condition to eliminate surface wrinkles from the screen.

Another object is to provide a locking device for a and stand in open position;

i Fig. 2 is an enlarged fragmentary sectional view of. one end of the screen casing; and

Fig. 3 is a sectional view taken as indicated on line 3-3 of Fig. 2.

In the embodiment illustrated, a telescoping supporting standard 10, generally maintained in upright position. upon a tripod base (not shown), is provided with a hook 11 from which a picture screen 12 may be suspended. The standard 10 has an extensible rod 13 telescoped within a tubular member 14 and held in varying degrees of extended position by a finger lock 15.

The picture screen 12 is secured at its bottom edge upon a curtain-type, spring-actuated roller 16 journaled within a protective casing 17. At its top edge the screen is lapped over a wooden or metallic rod 18 and sewn to itself by stitching 19. When the screen is not in use, the spring on the roller winds up the screen in much the same manner as in a Window shade. To place the screen in open position it is unwound by pulling it upwardly through a longitudinal slot 20 in the casing.

The top of the screen is preferably attached to the hook on the supporting standard in a manner that tends to distribute the pull of the screen evenly over the rod. An elongated bendable member 21 is preferably attached near each end of the rod 19 by rivets 22 and 23 so that downward forces exerted upon the rod 18 and the screen 12 in open position act through the two riveted points and upon the bendable member 21. A bail 24 is normally secured near the center of the member 21 and is placed over the hook 11 to support the movie screen in its extended position.

The protective casing 17 is mounted upon a bracket 25 which in turn is secured to the supporting standard 10. The bracket may be adjusted vertically on the supporting standard, and may also pivotally mount the casing so that the casing can be turned to a position parallel to 2,822,040 IPatentedFeb. 4, 1958 .the supporting-standard to facilitate carrying the picture screen standin collapsed position. i

The screen is stretched taut in open position by the device shown in Fig. 2. The end 26 of the protective casing 17 provides a bearing 27 for one of the journals 28 of the roller 16. A series of apertures 29 are annularly spaced about the end of the casing and are instrumental in locking the roller in varying degrees of rotation, as will later be seen.

A knob 30 is secured to the journal 28 of the roller 16 by a pin 31. An opening 32, preferably running longitudinally of the casing, traverses the knob 30, and can be made to coincide successively with each of the apertures 29 in the end of the. casing upon rotation of the knob. The opening is narrowed in a direction outwardly of the casing by the shouldered portion 33 formed in the knob 30.

A plunger, generally designated 34, is slidingly mounted in the opening 32, and is embraced by a spring 37 normally urging it outwardly of the casing. This outward movementis limited by contact between the shouldered portion 33 in the knob 30 and the enlarged portion 35 on the plunger 34. A sleeve 36 is preferably placed in the opening 32 adjacent the end of the casing. The sleeve and the enlarged portion 35 guide the plunger in its reciprocatory movement within the opening 32.

To stretch the screen, the knob 30 is rotated, and the screen is wound upon the roller 16. To lock the roller in its rotated position so that the screen may be maintained taut, the plunger is pushed inwardly as the knob is turned so that the neck 38 and the headed catch 39 of the plunger project through one of the apertures 29 in the end of the casing 26., Since the screen is under tension, it tends to unwind the roller, and the neck 38 of the headed catch 39 engages an edge of an aperture 29 to lock the headed catch in its projected position within the casing 17.

To unlock the rotatable member and roller from the casing, it is only necessary to turn the knob 30 slightly in a direction to add tension to the screen, and the headed catch 39 will immediately disengage and snap out of the aperture 29 under the action of the spring 37 embracing the plunger 33. The foregoing detailed description is given for clearness of understanding only and no unnecessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.

We claim:

1. In a picture screen adapted to be unwound from closed position on a curtain-type spring-actuated roller journaled in a protective casing to extended open position suspended from alsupporting standard, a one ivay locking device for securing said roller in a preselected position of rotation when said screen is tensioned while in extended position by rewinding upon the roller, comprising: a knob secured to a trunnion of said roller extending through the casing for rewinding the screen upon the roller and having an opening which will coincide with an aperture in one end of the casing; a plunger having a headed catch slidingly mounted in said opening, said headed catch adapted to be projected through said aperture to lock said roller and said tensioned screen against unwinding, said headed catch held in one-way locking engagement around an edge of the aperture by the tensioned screen tending to unwind the roller; and a spring normally urging said plunger toward released position, said plunger snapping out of said aperture upon further tensioning of the screen by a slight rewinding of the roller to disengage the headed catch.

2. A one-way locking device for a picture screen as specified in claim 1, in which movement of the plunger outwardly of the casing is limited by contact between a -shouldered -portionin the-knob -na-rrowingtheouter end 1 of the opening and an enlarged portion on the plunger guiding said plunger in the opening. 1 3. A one-wa'y locking device for a-picture-sereemas specified in claim 1, in-iwhich apln'r'alityof -apertures are annularlyspaced in one end of the" casing;- each of said apertures being adaptedto-receive the plunger 'wnicn locks therol-ler against unwinding.

4. A picture-screen comprisi-ng1-an"upright support; a flexible--screensecured-at ,itsopposite marginalend 'portions to a rod me'mber-a'nd a rotatablereelprovided with an outwardly extending trunnion,--saidrodmember andreel being secured t0, the upright supportat spaced points; arigidly fixedjournal member providing a bear- 'ing surfacefor' said reek-trunnion; a rotatable knob secured to said trunnionto wind, saidfiexible' screen upon the reel; and' cooperating latchingportions on saidknob and journalme'mber movableinto engagement to lock --saidreel in a preselected position'of rotation to stretch the screen taut between the rod member and the reel, the tension upon the flexible screen maintaining" said cooperating latching portions in' engagement.

5. A picture screen as specifiedin claim 4, in which an elongated bendable member is secured at spaced points to the rod member-andintermediate said'spaced points to the support, whereby tensioning forces on the flexible screen cause said bendable member to flex longitudinally and exert upward forces at said spaced points to stretch said screen taut between said rod member and reel.

6. A picture screen as specified in claim 4, in which the cooperating latching portions comprise a plunger slidable in a passage in the knob and a catch portion adjacent an aperture in-the journal member, said .passage and aperture being alignable by rotating said knob to apply a preselected tension to the flexible screen, said plunger locking saidr'eel in a preselected position of rotation by being projected through said. aperture inthe journal member,,the tension on said screen maintaining said plunger in locking engagement with saidcatch portion to stretch said screen taut .between said rod member andreel.

7. A picture screen as specified in claim 6,.in which a spring member normally urges the plunger out of locking engagement.

8. A picture screen comprising: an upright standard; an elongatedprote'ctive casing secured to said standard, said casing having a plurality of annularly spaced apertures in one ofits ends; a flexible screen having a rod member and a spring-actuated reel secured to its opposite marginal end portions to suspend said screen in open position on the standard, said reel being journaled for rotation in said casing; a rotatable knobsecur'ed tosaid reel at said oneend of the casing, said knob having a passage alignable with each of said apertures by rotating the knob to tension said flexible screen by winding the screen upon the reel; a'plunger'slidable in said passage, said plunger locking said. reel in a preselected position of rotation"-by-being-projected throughan aligned-aperture in the casing, the tension on said screen maintaining said plunger in locking engagement with the casing to stretch said screen taut between the rod member and the reel; and a spring member normally urging said plunger out of lockingengagement so that additional rotation of the reel when in locked position will permit the plunger; to: snap out of engagement iwith1the casing 9 A screen web having a spring actuated web tensioning-roller atone end-of said-screen, aslat at the; opposite end ofsaid web, a journal shaft extending from one end of said roller, a relatively stationary support comprising a bearingforzz'said 1shaft,.handle'means fast..on=said shaft for rotating said .roller manually, and latch means acting between said handle means and stationary support, said latch means being shiftable into and out of locking engagement with said support means, and being normally urged out of such engagement with said stationary .support and said latch means being held in locking engagement by tension on'said web.

' 10. A screen. web having a spring actuated web tensioning roller at one end'of said screen, a slat at the opposite end of.said web, a journal shaft extending from one end of said roller, a relatively stationary support comprising a bearing forsaid shaft, handle'means fast on said shaft for rotating said roller manually, coacting latchmembers respectively on said. handle means and said stationary support to lock said roller against rotation due to tension of said web, and a spring normally urging said members out of such locking relation.

11. In a picture screen comprising a screen web, having a roller at one end including a rewinding spring acting on said roller and a slat at the free .end of said web, a spring suspension for said slat having greater web pulling strength than that of said rewinding spring, a journal shaft at one end of said roller, a relatively stationary the pull on said web beyond that exerted by the rewinding spring and said latch means has been shifted manually into holding engagement with said support.

* References Citedin the file of this patent UNITED STATES PATENTS 

